SBIR-STTR Award

Our modular double-acting free-piston Stirling cryocooler features three separate cold head acceptors and heat rejection pathways and only one moving part per cold head. While our controller holds the piston amplitudes equal, the temperature presented to each acceptor may be different. Accordingly, the heat lifted by each acceptor can vary to meet load requirements. Some CubeSat payloads require the cooling of multiple loads at different temperatures. While the Phase I SBIR solicitation does state “a miniature two-stage cryocooler would be ideal for this type of application,” we believe that our single-stage, multi-acceptor cryocooler, and controller potentially provide a simpler solution that is easily adaptable to various CubeSat missions. Our preliminary estimates show that our proposed CubeSat cryocooler is competitive with existing single-stage “state-of-the-art” space-qualified units in terms of size, mass, and input power. However, our cryocooler can simultaneously service multiple cooling loads at different temperatures. The goal of this SBIR Phase I project is to complete the preliminary design for our CubeSat cryocooler and evaluate its multi-temperature performance as part of a simulated system, including a controller and vibration absorber. Potential NASA Applications (Limit 1500 characters, approximately 150 words): Space-based Cryocooling - Our cryocooler can be used to produce cooling in the temperature range of 60 - 200 K. Lower operating temperatures are possible via staging (as is described in our U.S. patent). Cooling applications that require multiple lift temperatures may benefit from using our cryocooler instead of multiple single-stage cryocoolers. The scalability of our machines down to small sizes makes them valuable for miniature “CubeSat” satellite-based sensor cooling. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Cryocooling - Our modular Stirling cryocoolers can be arranged to place heat acceptor surfaces near or surrounding the heat source. This ability to cool a central load and reject heat at the periphery would be ideal for zero boil-off re-condensation of liquid nitrogen, volatile fuels, and other substances or cooling superconducting magnetic bearings in support of flywheel energy storage systems. Duration: 6